The asymptotic winding at a negative puncture is one more than the winding of along small circles
ProvedFiniteEnergyPlane.hasWindInfAt_cylEndAt_of_hasLoopWindLet be a strictly star-shaped level, a -compatible complex structure on , and the induced almost complex structure on . Let be open and contain the punctured disc , , and let be smooth, nonvanishing and -holomorphic on . Suppose that the -component , read in Hryniewicz's global frame of , has winding number along every counterclockwise circle with . Then at seen as a negative puncture, in the cylindrical coordinates with traversed backwards (sign ),
This expresses the asymptotic winding at a negative puncture, which is defined in cylindrical coordinates, through the winding of along small counterclockwise circles about in the plane coordinate.
Formalization Note is V 1, is Jtilde H J, and in the global frame is piDs H u : ℂ → ℂ. The circles are z₀ + ccwLoop ρ t. The conclusion is HasWindInfAt H u (cylEndAt z₀) (-1) (k + 1): for all large the loop of has winding number . No energy bound or asymptotic hypothesis is assumed.
import Definitions.Def_FiniteEnergyPlane_Winding
namespace FiniteEnergyPlane
open MeasureTheory Metric Filter Topology
open scoped ContDiff ENNReal Real
/-- Let `u` be smooth, nonvanishing and `J̃`-holomorphic on an open set `U` containing the punctured
disc `B(z₀, r) \ {z₀}`, and suppose that `π ∂ₛu` (in the global frame, `piDs H u`) has winding
number `k` along every counterclockwise circle `t ↦ z₀ + ρ e^{2πit}` with `0 < ρ < r`. Then the
asymptotic winding of `u` at `z₀`, viewed as a negative puncture in the cylindrical coordinates
`cylEndAt z₀` (sign `-1`), is `k + 1`. -/
theorem hasWindInfAt_cylEndAt_of_hasLoopWind (H : V 1 → ℝ) (hH : IsStrictlyStarShapedLevel H)
(J : V 1 → V 1 →L[ℝ] V 1) (hJ : IsCompatibleXiStructure H J) (U : Set ℂ) (hU : IsOpen U)
(u : ℂ → V 1) (hu : ContDiffOn ℝ ∞ u U) (hu0 : ∀ z ∈ U, u z ≠ 0)
(hhol : JHolomorphic.IsJHolomorphicOn (Jtilde H J) U u) (z₀ : ℂ) (r : ℝ) (hr : 0 < r)
(hrU : ball z₀ r \ {z₀} ⊆ U) (k : ℤ)
(hk : ∀ ρ ∈ Set.Ioo 0 r, HasLoopWind (fun t => piDs H u (z₀ + ccwLoop ρ t)) k) :
HasWindInfAt H u (cylEndAt z₀) (-1) (k + 1) := by
sorry
end FiniteEnergyPlane